Chapter5

DeitelC/Chapter5/fibonacci.c

@@ -0,0 +1,29 @@
+#include <stdio.h>
+
+unsigned long long int fibonacci(int n);
+
+int main (void){
+
+puts("Enter fibonacci step!");
+int n;
+
+if(!scanf("%d", &n)){
+    puts("invalid");
+    return 1;
+    }
+
+printf("%d. step of fibonacci: %llu\n", n, fibonacci(n));
+
+return 0;
+}
+
+unsigned long long int fibonacci(int n) {
+
+if(n == 0 || 1 == n){
+return n;
+} else {
+
+return fibonacci(n - 1) + fibonacci (n - 2);
+}
+
+}